The assignment of the MUDs to different types (Dirt, Dyrt, iDirt, CDirt) is not very helpful to anyone anyway. The borders are fuzzy and some MUDs are a combination of code from all of them. Some MUDs have different names for their code bases, because they have added more or less new code, which distinguishes their code from the original.
For example Dragon and Phoenix are both listed as Dyrt, although they more distinct from each other, than CDirt is from iDirt. I would suggest that this codebase system be abandoned and replaced with a more informative method, which for example lists certain core features and differences between the MUDs.
